According to the present invention, apparatus for forming a frontal toothing on an inner ring of a wheel hub by means of plastic deformation is thus provided.
The fact that, according to the invention, the frontal toothing is impressed by means of a plurality of knives, independently carried by a single, substantially rigid plate, and which are impressed onto the already upset collar in sequence, by moving them independently from one another by pressing respective heads of the knives by means of an orbital forming tool, surprisingly allows to obtain frontal toothings by means of plastic deformation, in which the tooth profile is kept substantially constant, while ensuring a higher dimensional accuracy of the teeth thus obtained. Therefore, better, more accurate couplings are obtained between the inner ring of the wheel hub and the constant velocity joint, which allow more effective, quieter and higher capacity torque transmissions to be obtained.
Furthermore, the required frontal toothing is obtained with low energy consumption.